I'm happy you had better luck than I did. It was 4° F when I opened the main door and saw similar crystals on the inside glass of the storm door. Of course I closed the main door and went to get my SX50, RAYNOX and tripod. Quickly, but alas not quickly enough. The amount of heat that was now trapped between the two doors had already begun to degrade the crystals when I reopened the main door. If I had went out another door, I could have photographed the crystals through the glass from the outside. Lesson learned for the next time, but on the other hand I hope we don't have any more 0° F weather.